Clothes dryer



Nov. 4, 1958 s. L. MCMILLAN CLOTHES DRYER 2 Sheets-Sheet 1 Filed June 10, 1955 FIG. 1

INVENTOR.

STEPHEN L. Mc MILLAN HIS' ATTORNEY Nov. 4, 1958 s. L. M MILLAN 2,858,621

CLOTHES DRYER Filed June 10, 1955 2 Sheets-Sheet 2 FIG. 3 F 314.

FIG. 4

IN VEN TOR.

87 STEPHEN L. MCMILLAN 9 75 76 as BY 86 35 HIS ATTORNEY United States Patent 2,858,621 CLOTHES DRYER Application June 10, 1955, Serial No. 514,583 3 Claims. .(Cl. 34-75 This invention relates to clothes drying machines and-more particularly to such machines provided with means for conditioning the drying air.

In one type of domestic laundry drying machine, air which has been heated picks up moisture and lint in passing through the clothes. For efi'iciency and to prevent discharge ofvmoisture and lint into the house, it is advantageous to recirculate' the drying air continuously within the. machine, and to reheat it during each cycle after it passes through the clothes. This air recirculation raises the problem of disposing of the entrained moisture and lint in the drying air after passing through'the clothes and before it is reheated. Accordingly, it is a primary object of this invention to provide, in conjunction with a clothes drying machine, means to remove moisture and lint from air used in the drying system.

It is also an object of this invention to provide an improved construction for the removal of moisture from the air expended during the drying process so that only relatively dry' air is supplied to the clothes container.

Still another object of this invention is to provide an arrangement by which the air employed in the drying system is thoroughly cleansed of entrained lint in order to insure thatonly clean heated air is supplied to the clothes container.

A further object of the invention is to provide automatic, efiicient, and economical means whereby the moisture and lint removed from the drying may be effectively eliminated from the drying machine.

In accordance With'one aspect of my invention, a clothes dryer with heating means and air circulating means is equipped with a plurality of rotating partially liquid-immersed disks place in the air flow path for extracting the entrained moisture and lint from the circulating air. The invention includes a further aspect of an automatic control over the disk wetting arrangement to maintain the desired water level and water temperature.

The'features of my invention believed to be novel' are set forth with particularity in the appended claims. Therinvention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection wit-h the accompanying drawings, in which: Fig. 1 is a front elevation view, partially sectionalized, of a clothes drying machine embodying my invention;

Fig. 2 is a partial rear elevation view of the machine of Fig. 1 with a rear panel removed to illustrate detail;

Fig. 3 is a view taken substantially along line 3--3 of Fig. 1;

Fig. 4 is a view taken substantially along the line 4-4 of Fig. 3; and

Fig. 5 is a schematic wiring diagram for the machine illustrated by Figs. 1-4.

While not necessarily limited thereto the present invention is, described. as particularly adapted for use ice in conjunction with a clothes dryer of the type having a tumbling drum or basket 1 rotatable about a substantially horizontal axis within an outer enclosing cabinet or casing. Basket 1 may include a peripheral foraminous wall 2, a back end wall, and a front end wall 3 having an access opening 4 therein. The outer cabinet in the usual manner includes side walls 5, atop 6, and a suitable supporting base structure 7. The front wall of the machine includes a hinged door 8 for providing access to the machine. Abacksplash 9 is located at the top of the machine and has mounted thereon a control panel 10. Control knobs 11, 12 are provided'on the control panel 10. The dryer is provided with an innercasing having a partially arcuate side wall 13, a front Wall 14 (Fig. 3) and a rear wall 15 (Figs. 2 and 3).

In a manner well known in the art, basket 1 is supported for rotation about a horizontal axis and is driven by a motor 16 having an output drive pulley 17 attached to its shaft. A belt 18 connected to pulley 17 drives a movable pulley 19 which is slidably mounted on a bracket 20. A spring 21 attached to this bracket loads an output pulley 22 secured thereto. This maintains tension on belt 18 and also on both pulley 19 and the belt 23 which drives a pulley 24 attached to the basket shaft. Thereby the basket is rotated to provide tumbling of the clothes placed therein.

Motor 16 may also drive an air circulating means such as the fan 25 (Fig. 3) attached to the motor shaft, which forces air within the machine over a heater 26 and through the foraminous cylindrical wall 2 of basket 1 in order to evaporate the moisture from clothes being tumbled Within the basket. It is to be understood in the type of drying machine thus far described that the air 'is recirculated within the machine continuously and that substantially no air is drawn in or discharged externally of the machine. It will be noted that the fan may be eliminated and other types of air circulating means may be employed, or the air may be circulated by means of the tumbling drum alone.

In accordance with this invention, means are provided for conditioning the air used during the drying operation. More specifically it is contemplated that the arrangement of this invention be used to remove moisture and lint from the drying air after it has come into contact with the clothes and before it is reheated within the machine.

I have shownas a specific example of the invention a condensing chamber 27 positioned within the lower portion of the machine inner casing between the front wall 14 and rear panel 15. The chamber has a top wall 28, a bottom wall 29, side walls 30 and 30a, and end walls 31 and 31a. A portion of the chamber top wall is removed to provide an entrance 32 for the air leaving the basket. One or more parallel shafts 33, three as shown in the illustrated embodiment, are rotatably mounted in a horizontal plane within the chamber 27, and a plurality of disks 34 are stacked on each shaft.

, The disks preferably are intermeshed so that alternate disks are on adjacent shafts.

As shown in Figs. 2 and 3, the center shaft is driven from a sprocket 35 on the basket shaft by a chain 36 connected to a sprocket 37 at one end of the center disk shaft. The other disk shafts are driven from the center disk shaft in the same direction and at the same speed by means of pulley belts 38', 39 connected to pulleys 40, 41 on the adjacent shafts. Obviously, other types of drive means and arrangements may be employed to rotate slowly the disk shafts. In one specific machine built in accordance with this invention, the condenser had three disk shafts, and a spacing of approximately two and onehalf inches between shaft centers was found to be satisfactory. .Although a wide range of disk diameters can moisture condensation. .the disks is constantly washed off as the disks rotate.

be selected, a diameter of approximately four inches with a disk thickness of .02 inch will prove to be quite satisfactory. In this aforesaid embodiment, separating wash- A liquid reservoir "42 with slanted upstanding side walls 43,44 is provided within the chamber 27 and is arranged so that when it is filled with water the lower ,portion of each of'the disks is immersed in liquid. The

exposed portion of the disks contacts the moist air entering the chamber through entrance 32 and a transfer of .moisture andlint from the air to the disk occurs. ,disks are cooled by the liquid as they are rotated, e.

The

from the basket shaft through the chain and sprocket drive,'so that cool surfaces are constantlypresented for Additionally lint collecting on .A.transverse partition or wall is provided within the chamber 27 adjacent the reservoir wall 43 and extending at an angle thereto. This wall 45 forms with the wall 43 a liquid compartment or vat 46 connected to a liquid supply line 47. When liquid flows into the vat 46 it fills until liquid spills over wall43 intoreservoir 42. The reservoir is then filled until liquid spills over the wall 44, this spillage thereafter maintaining the proper liquid within the reservoir. The liquid spilling over wall 44 is received by an outlet compartment or chamber 48 of the condenser 27 and from there it is removed from the machine through a drain 48a. To prevent flooding in the event that the chamber 48 fails to drain properly, a float switch 49 is provided. This switch is mounted in the wall 31a and has a float 50 extending into the condenser chamber 48. When the liquid level rises the float moves upwardly pivoting a switch arm 51 to open contacts within a switch assembly 51a. This breaks the circuit to a solenoid actuatedvalve 52 so that the valve moves to its normal position and shuts off the liquid flow through inlet 47.

An opening 53 is located in the rear inner casing panel 15 through which air discharged from the condenser 27 can pass through its air outlet passageway 53a-as shown by the arrows in Fig. 3 under the action of the air circulation fan 25 mounted on the motor 16. The fan is positioned within another opening 54 in the panel 15 which permits the air to be drawn over the motor 16 into a chamber 55 formed by the inner casing wall 13 and an arcuate deflector 56. Air is prevented from leaving the rear of the machine by a panel 57 attached to the edges of the wall 15 and forming with the wall 15 a passageway leading between the openings 53 and 54. The panel 57 also covers the driving arrangement for the disks and basket (Fig. 3).

Air in the chamber 55' passes upwardly between the deflector56 and wall 13 over the heaters 26 and into the basket 1 through the foraminous wall 2 absorbing moisture and picking up lint from the clothes therein.

A thermostat 58 is located within the reservoir 42 and is responsive to the temperature of the liquid contained therein. When the temperature of the liquid rises to a predetermined point due to the absorptionof heat from the rotating disks, the thermostat acts to energize the valve 52 in the manner explained hereinafter to open the liquid supply to the condenser 27, which supply is normally closed. Clean cool water is then admitted whereby the hot liquid and lint in the reservoir are discharged through the drain 48a in the manner described above.

Referring now to Fig. 5, I have indicated schematically a control system for my machine arranged in accordance with my invention. Electrical power is supplied for operation of the machine at a terminal block 59 including terminals for 220 v. incoming supply lines 60 and 61 anda neutral line 62. A fusible link 63 may be-employed in the neutral line in the usual manner. The power supply lines 60 and 61 extend to a timer control assembly indicated generally at 64 and are connected thereto at terminals 65 and 66. This timer control 64 is located within the control panel 10 mounted on the backsplash 9 as shown in Fig. l. The electrical circuit corresponding to input terminal 65 extends to a cam operated switch 67; while the circuit from terminal 66 extends to a second cam "operated switch 68. Switch 67 has associated therewith an operating cam 69 having valleys and rises as shown to operate the switch from its open to its closed position. Similarly, switch 68 is operated by a cam 70. These cams may be rotated by a timer motor 71, such asa synchronous clock motor, or may be manually rotated by the control knob 11 mounted on the control panel 10 (Fig. 1). Timer 71 normally rotates the cams in a clockwise direction.

:However, a slip clutch 71a is positioned between the timer and the knob v11 in a manner well known in the art so that knob 11 maybe employed to manually rotate the cams in either direction to change the period of dryer operation. Timer output terminals 72 and 73, upon closure of the timer switches, are connected to the two sides of the power supply line. A third terminal 74 is an electrical neutral connection for one side of the timer motor 71, whereby this motor may be operated on 110 volts. The other side of the'timer motor 71 is connected through-a line 74a to terminal 72, and thus to line 65 through switch-67, so that the motor 71 is suppliedwith 110 volts between one side of the supply andneutral.

Theelectn'calheater assembly 26 includes two separate heater sections 75 and 75a having a common terminal 76 and end terminals '77 and 78, whereby the heater assembly may be operated with both sections-in electrical parallel, or by means .of the manually operable temperature selector switch 79, may be operated with only one section of the heater energized. The position of the selector switch 79 is controlled by the manual knob 12 shown in Fig. l mountedon the control panel 10 attached to'the backsplash 9. Theelectrical heaters furthermay be under the control of a cycling temperature control thermostat 80 and a safety thermostat 81. The particular construction and arrangement of this temperature control forms .no part of the present invention, but is disclosed and vclaimed in the copending application 0f Leonard O. Mayhan, S. N. 389,039, filed December 14, 1953 and assigned to the General Electric Company, assignee of this application.

Motor 16 includes the usual main or run winding 82 and a start winding 83. The main winding is connected to one side of the electrical power line by means of motor terminal .84 and to the electrical neutral by motor terminal 85. The'motor'therefore is operated on 110 volts. Motor start winding 83 is connected to the power supply line through a switch including contacts 86 and 87 adapted to be bridged by an armature 88 of a centrifugal mechanism 89. When the motor is at rest, armature 88 completes the circuit to the start winding from motor terminal 84 to motor terminal 85. However, as soon as the motor comes up to speed, centrifugal mechanism 89 lifts armature 88 to open the start winding circuit. As clearly shown by Fig. 5, this same centrifugal mechanism 89 and armature 88 completes the heater circuit through contacts 90 and'91 when the motor is running.

For safety reasons, it is preferred to have the entire machine under the control of a door operated switch 92 (Fig. 5) which is in its closed position when the door 8 is closed permitting operation of the dryer, and is opened when the door is opened to shut down timer motor -71, main drive motor 16 and heater assembly 26. This switch 92 specifically is connected in series circuit relation in the line 93 connecting timer terminal 74'and motor terminal to the electricalneutral 62.

The thermostat 58, float switch 49, 'and the solenoid actuated water valve 52 are connected in series be'tween the timer output terminal 72 and the electrical neutral line 93. They are thus connected across 110 volts when the cam operated motor control switch 67 and the door switch 92 are closed. The thermostat which is normally open closes at a predetermined high temperature of the reservoir liquid to energize the water valve solenoid. The float switch 49 is normally. closed and opens the contact in the switch assembly 52 only when the water level is excessive, thereby to prevent the energization of the solenoid valve 52. T

In operation a quantity of laundry to be dried is placed within the tumbling basket and .door 8 is shut closing door switch 92. A rotation of cams 69 and 70 in a clock- Wise direction is then etfected by control knob 11 to close "both switches 67 and 68. The timer motor 71 is thereby energized by a circuit through switch 67, terminal 72, line 74a, terminal 74, neutral line 93, switch 92, and neutral 62 so that it drives the cams in a clockwise direction to time the length of the drying operation. A circuit is also completed from line 60 through switch 67 to line 94 connected to motor terminal 84. Power is thus supplied directly to main winding 82 of the motor and to start winding 83 through the centrifugally operated switch contacts 86 and 87 and the motor circuit is completed through motor terminal 85, neutral line 93 and the door operated switch 92, to the electrical neutral 62. As soon as the motor comes up to speed, the circuit to start winding 83 is opened by the centrifugal mechanism as previously described. This same motion of the centrifugal mechanism is effective to bridge contacts 90 and 91 by armature 88. The circuit for the heating elements is therefore closed from line 60 through switch 67 to line 94, motor terminal 84, contact 91, armature 88, contact 90, a motor terminal 95, line 96, to the common terminal 76 of the heating element.

Assuming that the temperature selector switch has been set to the hot position closing switch 79, parallel circuits are completed from terminal 76 through both sections 75 and 75a of the electric heating element, to a line 97. From line 97 the heater circuit is completed through safety thermostat 81, 'line 98 to the cycling temperature control thermostat 80, the thermostat 80 itself, line 99 to terminal 73 of the timer, cam operated switch 68, and terminal 66 corresponding to the other side of the electrical supply line 61. It may be noted in this connection that motor 16 must be running before power is supplied to the electrical heaters. It may also be noted that the door operated switch 92 is in both the motor circuit and in the circuit of timer motor 71. Therefore, if at any time during operation of the machine the door 8 is opened, both motors are immediately stopped, and in view of the fact that the heaters are under control of a centrifugal switch in motor 16, the heaters likewise are deenergized.

During the operation of the main drive motor, and thus in my preferred embodiment during the entire drying operation, the disks 34 are rotated slowly to condense moisture and entrap lint from the drying air. The liquid in the reservoir 42 cools the disks and washes off the lint. When a predetermined high temperature is reached, the thermostat 58 closes to energize the valve solenoid and thereby open the liquid valve 52 admitting cool water to vat 46 from supply line 47. The cool water then flows over wall 43 into the reservoir 42 displacing the warm water therein. The arm water overflows wall 44 into compartment 48 and drains through drainpipe 48a. The flow of cool water continues until the temperature of the water in the reservoir has dropped sufiiciently for the thermostat 58 to open and shut off valve 52. Thus, the water is maintained sufficiently cool where efficient condensation can take place between the air and disks. float switch 49 prevents the solenoid from being energ'ized in the event the drain is clogged.

Operation of both motor 16 and heaters 26 continues 6 until such time as timer motor 41 rotates cam 70 to a position opening switch 68, thereby opening the circuit to the heating elements. Switch 67 remains closed for a short period of time following the opening of switch 68 to continue the drive motor 16 in operation for a period of time commonly referred to as the cool-down. After approximately five minutes of cool-down, the valley in cam 69 opens switch 67 to deenergize drive motor 16 and timer motor 71 and thereby terminate dryer operation.

In operation, it is found that with the wet-disk condenser a rapid and eflicient transfer of moisture takes place from the drying air discharged from the basket thus providing a more rapid removal of moisture from the wet clothes. In addition the air is thoroughly cleansed of entrained lint and dirt particles resulting in cleaner falblrics after the drying operation than heretofore poss1 e.

While a specific embodiment of the invention has been disclosed herein, it is obvious that many other modifications may be-made by those skilled in the art without actually departing from the invention. For example, a fixed flow orifice can be used instead of the thermostat as a water control means, a screen being disposed upstream from the orifice to prevent clogging thereof. Also, one or more disk shafts can be used and the number, diameter, and spacing of disks on each shaft can be varied. It is therefore aimed in the appended claims to cover all such equivalent variations as come within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a clothes dryer, a clothes container, heating means, means for passing air over said heating means and through said container, a liquid reservoir, a plurality of disks arranged for rotation within said reservoir with a portion of each disk below the liquid level in said reservoir, means directing air flow from said container over the exposed area of said disks, liquid supply means and temperature sensitive means within said reservoir for controlling said supply means, said temperature sensitive means operating at a predetermined liquid temperature to admit liquid to said reservoir through said liquid supply means until a predetermined lower liquid temperature is reached in said reservoir, whereupon said temperature sensitive means shuts ofl the supply to said reservoir.

2. In a clothes dryer, a clothes container, heating means, means for passing air over said heating means and through said container, a liquid reservoir, a plurality of disks arranged for rotation within said reservoir with a portion of each disk below the liquid level in said reservoir, means directing air flow from said container over the exposed area of said disks, liquid supply means, temperatu're sensitive means within said reservoir for controlling said supply means, said temperature sensitive means operating at a predetermined liquid temperature to admit liquid to said reservoir through said liquid supply means until a predetermined lower liquid temperature is reached in said reservoir, whereupon said temperature sensitive means shuts off the supply to said reservoir, and liquid level control means for said reservoir.

3. In a clothes dryer, a clothes container and a closed air recirculation system for continuously withdrawing moist air from said container and returning warm dry air thereto, said recirculation system including condensing means for condensing moisture from the moist air leaving said container, heating means for subsequently reheating the air before it returns to said chamber, conduit means for guiding the air from said container, through said condensing means and said heating means, and back to said container, and air circulating means for moving the air through said system, said condensing means comprising a liquid reservoir and a plurality of disks arranged for rotation in said reservoir, said disks being mounted on a plurality of parallel shafts and the disks on adjacent shafts being intermeshed, with the lower portions of said disks being arranged to dip into the liquid in said reservoir midified, liquid supply means for admitting fresh'liquid to said reservoir, and drain means for draining the used liquid from said reservoir as said fresh liquid is admitted.

,References Cited in the file'of this patent UNITED STATES PATENTS Hunter Mar. 6, :Hutzel 'Oct. 9, Pugh Oct. 19, Clark Nov. 30,

FOREIGN PATENTS Germany Nov. 4, 

